Hood latch with self-retracting secondary latch release arm

ABSTRACT

A latch assembly ( 10 ) has a housing having a mouth. A ratchet ( 12 ) is pivotally mounted to the housing and is movable to cooperate with the mouth to pivot between an open condition, a primary closed condition and a secondary closed condition for receiving, engaging and cinching a keeper of a striker. The ratchet ( 12 ) is biased to the open condition. A pivotally mounted pawl ( 40 ) is biased into engagement with the ratchet for releasably retaining the ratchet in the primary closed condition. A secondary release arm ( 20 ) is mounted to rotate about a first axis and a second axis. The secondary release arm ( 20 ) is rotatable about the first axis between a retracted position and an extended position, and is rotatable out the second axis between an engaging position and a disengaging position. The secondary release arm ( 20 ) is biased to the retracted position and biased to the engaging position. The secondary release arm ( 20 ) interengages with the ratchet ( 12 ) for coupled movement therewith from the primary closed condition to the secondary closed condition effecting movement of the secondary release arm ( 20 ) from the retracted position to the extended position upon the pawl ( 40 ) being rotated to disengage from the ratchet ( 12 ). Upon moving the secondary release arm ( 20 ) from the engaging position to the disengaging position, the secondary release arm ( 20 ) disengages from the ratchet ( 12 ) for independent movement enabling the ratchet ( 12 ) to rotate from the secondary closed condition to the open condition and back to the primary closed condition. The secondary release arm ( 20 ) also rotates from the extended position to the retracted position.

FIELD OF INVENTION

[0001] This invention relates to a hood latch for a vehicle. Inparticular, this invention relates to a hood latch having aself-retracting secondary arm.

BACKGROUND OF INVENTION

[0002] Vehicle hood latch systems are well known in the art. Typically,a vehicle hood or trunk deck will have a latch for engaging and cinchingonto a striker. The latch will have a rotatably mounted ratchet engaginga pawl in a ratchet relation. The ratchet cooperates with a mouth of thehousing to pivot between an open and closed condition for receiving,engaging and cinching a keeper of a striker. The pawl retains theratchet in the closed and cinched conditions.

[0003] Hood latches are required to have a secondary latching mechanismand a primary latching mechanism. The primary latching mechanism isoperably from inside the vehicle, normally under the dashboard. Asecondary latching is only operable from the outside. The secondaryrelease lever is accessible only after the primary latching mechanismhas been deployed, but is usually in a deployable position even thoughit is not accessible. In many cases, the location of the arm isdifficult to find requiring the operator to probe blindly or bend overto look for the arm.

[0004] It is known to provide a release lever on the secondary latchingmechanism that is presented only upon the release of the primary latch.Examples of such latch mechanism are described in U.S. Pat. Nos.4,961,601; 4,991,884; 5,000,493 and 5,141,265. However, such mechanismsrequire complicated linkages and levers, adding costs to the latch. As aresult, the use of self presenting secondary release arms has beenlimited.

SUMMARY OF THE INVENTION

[0005] The disadvantages of the prior art may be overcome by providing ahood latch assembly for a vehicle having a simple mechanism for selfpresenting a secondary release arm upon releasing of the primary releaseand which retracts upon secondary release of the hood.

[0006] It is desirable to provide a hood latch assembly having aretracting secondary release that is retracted independently of theclosing of the hood minimizing inertial forces on the secondary releaselever.

[0007] According to one aspect of the invention, there is provided alatch assembly that has a housing having a mouth. A ratchet is pivotallymounted to the housing and is movable to cooperate with the mouth topivot between an open condition, a primary closed condition and asecondary closed condition for receiving, engaging and cinching a keeperof a striker. The ratchet is biased to the open condition. A pivotallymounted pawl is biased into engagement with the ratchet for releasablyretaining the ratchet in the primary closed condition. A secondaryrelease arm is mounted to rotate about a first axis and a second axis.The secondary release arm is rotatable about the first axis between aretracted position and an extended position, and is rotatable about thesecond axis between an engaging position and a disengaging position. Thesecondary release arm is biased to the retracted position and biased tothe engaging position. The secondary release arm interengages with theratchet for coupled movement therewith from the primary closed conditionto the secondary closed condition effecting movement of the secondaryrelease arm from the retracted position to the extended position uponthe pawl being rotated to disengage from the ratchet. Upon moving thesecondary release arm from the engaging position to the disengagingposition, the secondary release arm disengages from the ratchet forindependent movement enabling the ratchet to rotate from the secondaryclosed condition to the open condition and back to the primary closedcondition. The secondary release arm also rotates from the extendedposition to the retracted position.

[0008] According to another aspect of the invention, there is provided alatch assembly having a secondary release arm that includes a platecommonly mounted for pivotal movement therewith. The plate interengagingwith a ratchet. The secondary release arm is pivotally mounted in anover center and overlapping relation with the plate, enabling the plateto pivot without causing the secondary release lever to pivot, andcoupling the secondary release lever to effect pivoting of the plate.

DESCRIPTION OF THE DRAWINGS

[0009] In drawings which illustrate embodiments of the invention,

[0010]FIG. 1 is a perspective view of the latch assembly of the presentinvention;

[0011]FIG. 2 is a perspective view of the reverse side of the latchassembly of FIG. 1, with the back plate removed;

[0012]FIG. 3 is a perspective view of the latch assembly, similar toFIG. 2, but from a lower angle of view to illustrate the release levermounting assembly.

DESCRIPTION OF THE INVENTION

[0013] Referring to FIGS. 1 and 2, the latch assembly 10 of the presentinvention generally has a ratchet or ratchet 12 which has a hook 15 andwhich is rotatable mounted on a pin 14 to pivot between an opencondition, a secondary closed condition and a primary closed conditionto grip a keeper of a striker. Spring 18 attaches to the ratchet 12 ataperture 17 and to housing 16 to bias ratchet 12 to a release position.Pin 14 extends between housing 16 and back plate 22.

[0014] Ratchet 12 has a series of detents 24 and 26 corresponding to theopen condition and the primary closed condition. Ratchet 12 has a tab ortongue 28. Preferably, the leading edge of the tab 28 is contoured.Ratchet 12 cooperates with the mouth of the housing 16. Pawl 40 isbiased to engage ratchet 12 in a ratchet relation. The ratchet 12cooperates with a mouth of the housing 16 to pivot between the open andprimary closed or latched condition for receiving, engaging and cinchinga keeper of a striker. The pawl 40 retains the ratchet 12 in the latchedcondition.

[0015] Secondary release lever 20 is mounted on a mounting assembly toprovide two degrees of movement. Release lever 20 has a U-shaped basethat is received between arms of upwardly extending U-shaped pivot mount30. Pivot 30 is pivotally mounted on flange 21 of housing 16 by pin 23to rotate about a first axis, providing a side to side movement of thesecondary release lever 20 and plate 36. Pivot pin 34 pivotally connectsrelease lever 20 to the mounting assembly about a second axis to providean up and down movement as will be explained later. Preferably the firstaxis is orthogonal to the second axis.

[0016] Spring 32 extends between flange 21 and U-shaped pivot 30 to biasthe mounting assembly, including release lever 20, to the retractedposition. In the retracted position, release lever 20 will be in thesame general plane as the housing 16. U-shaped pivot mount 30 pivotallyreceives plate 36. Plate 36 has a U-shaped base that is fitted betweenthe arms of the U-shaped pivot mount 30 and release lever 20. Plate 36has an aperture 37 that is sized to receive tab 28 of ratchet 12.

[0017] Plate 36 and secondary release lever 20 has a common pivot.Preferably, secondary release lever 20 and plate 36 extend from oppositesides of the common pivot. Secondary release lever 20 extends in an overcenter and overlapping relation with plate 36 so that plate 36 may pivotindependently of the secondary release lever 20, but not vice versa. Inother words, plate 36 may pivot without causing release lever 20 topivot, but pivoting of release lever 20 will cause pivoting of the plate36.

[0018] Spring 38 extends between release lever 20 and plate 36 to biasplate 36 to cooperate with release lever 20. Spring 39 extends betweenthe plate 36 and U-shaped mount 30 to bias the plate 36 upwardly forengagement with the ratchet 12.

[0019] The various elements have tabs for engaging the springs that makeup the present invention. The tabs are positioned in a manner well knownin the art to provide the requisite biasing as described herein.

[0020] Release pawl 40 is pivotally mounted on pin 42 that extendsbetween the housing 16 and back plate 22. Spring 44 biases the pawl intoengagement with the ratchet 12. Pawl 40 is connected to a release wire46 in a manner well known in the art.

[0021] Housing 16 has a semi-tubular channel 48 which houses spring 50which biases ratchet 12 to the release position.

[0022] In the release condition, the secondary release arm 20 is in theretracted condition. Upon closing the hood, the ratchet 12 receives akeeper mounted on the hood. A hood closing force will cause the ratchet12 to rotate against the bias of spring 18 and 50 until release pawl 40abuts against detent 26, securing the hood in the latched condition. Tab28 of ratchet 12 will engage plate 36 and will urge the plate 36 todeflect against the bias of spring 38 until tab 28 is received withinaperture 37.

[0023] Upon primary release of the ratchet 12 by retracting cable 46from inside the vehicle, pawl 40 will rotate releasing ratchet 12 fromdetent 26. Since ratchet 12 is in engagement with the release lever 20,rotation of the ratchet 12 is a releasing direction will cause therelease lever 20 to pivot from the retracted position to the secondaryrelease position until the plate 36 contacts stop 52. In the secondaryrelease position, the release lever 20 will extend forwardly of thelatch assembly and thus accessible from the front of the vehicle. Uponurging the release lever in an upward direction, the plate 36 will beurged away from the ratchet 12 until tab 28 disengages from the aperture37. The bias of spring 18 will rotate the ratchet 12 to the releasecondition, fully releasing the keeper and allowing the hood to beopened. Detent 24 will abut release pawl 40. Additionally, the bias ofspring 32 will rotate the release lever 20 from the release positionback to the retracted position.

[0024] The principal advantage of the present invention is that theretraction of the secondary release lever is not dependent on theclosing of the hood.

[0025] The preceding specific embodiment is illustrative of the practiceof the present invention. It is to be understood, however, that otherexpedients known or apparent to those skilled in the art or disclosedherein may be employed without departing from the scope of theinvention.

What is claimed:
 1. A latch assembly comprising: a housing having amouth, a ratchet pivotally mounted to the housing and movable tocooperate with the mouth to pivot between an open condition, a primaryclosed condition and a secondary closed condition for receiving,engaging and cinching a keeper of a striker, the ratchet biased to theopen condition, a pivotally mounted pawl having biasing means forbiasing the pawl into engagement with the ratchet for releasablyretaining the ratchet in the primary closed condition, a secondaryrelease arm mounted to rotate about a first axis and a second axis, saidsecondary release arm rotatable about said first axis between aretracted position and an extended position, said secondary release armrotatable about said second axis between an engaging position and adisengaging position, said secondary release arm biased to the retractedposition and biased to the engaging position, said secondary release arminterengaging with said ratchet for coupled movement therewith from theprimary closed condition to the secondary closed condition effectingmovement of said secondary release arm from the retracted position tosaid extended position upon said pawl being rotated to disengage fromsaid ratchet, and upon moving said secondary release arm from saidengaging position to said disengaging position, said secondary releasearm disengages from said ratchet for independent movement enabling saidratchet to rotate from the secondary closed condition to the opencondition and back to the primary closed condition, and enabling saidsecondary release arm to rotate from the extended position to theretracted position.
 2. A latch assembly as claimed in claim 1 whereinsaid secondary release arm interengages with said ratchet upon saidratchet moving back to said primary closed condition.
 3. A latchassembly as claimed in claim 2 wherein secondary release arm includes aplate commonly mounted for pivotal movement therewith for rotation aboutsaid second axis, said plate interengaging with said ratchet, saidsecondary release arm engages with said plate in an over center andoverlapping relation enabling said plate to pivot without causing saidsecondary release lever to pivot, and coupling the secondary releaselever to effect pivoting of the plate by said secondary release lever.4. A latch assembly as claimed in claim 3 wherein said plate has anaperture and said ratchet has a tab positioned to interengage with saidaperture when said ratchet moves back to said primary closed condition.5. A latch assembly as claimed in claim 4 wherein said housing has astop for limiting movement of said secondary release arm when saidsecondary release arm is in said extended position.
 6. A latch assemblyas claimed in claim 5 wherein said secondary release arm extendssubstantially parallel to said housing when in said retracted positionand extends substantially perpendicular to said housing when in saidextended position.
 7. A latch assembly as claimed in claim 1 comprisinga U-shaped mount pivotally mounted on said housing for rotating aboutsaid first axis, said secondary release arm pivotally mounting to saidU-shaped member for rotating about said second axis.
 8. A latch assemblyas claimed in claim 7 wherein secondary release arm includes a platecommonly mounted for pivotal movement therewith for rotation about saidsecond axis, said plate interengaging with said ratchet, said secondaryrelease arm engages with said plate in an over center and overlappingrelation enabling said plate to pivot without causing said secondaryrelease lever to pivot, and coupling the secondary release lever toeffect pivoting of the plate by said secondary release lever.
 9. A latchassembly as claimed in claim 8 wherein said plate has an aperture andsaid ratchet has a tab positioned to interengage with said aperture whensaid ratchet moves back to said primary closed condition.
 10. A latchassembly as claimed in claim 9 wherein said housing has a stop forlimiting movement of said secondary release arm when said secondaryrelease arm is in said extended position.
 11. A latch assembly asclaimed in claim 10 wherein said secondary release arm extendssubstantially parallel to said housing when in said retracted positionand extends substantially perpendicular to said housing when in saidextended position.